metricsd: Give directory group permissions

Since crash_reporter gets run as root, in order to use metrics_lib
it has to use group permissions to interact with metrics files.

Bug: 23406290
Change-Id: Ie9556233105312f973c0a3e018fc0305a466148d
diff --git a/metricsd/init.metrics_daemon.rc b/metricsd/init.metrics_daemon.rc
index ad78ea5..73ce673 100644
--- a/metricsd/init.metrics_daemon.rc
+++ b/metricsd/init.metrics_daemon.rc
@@ -1,5 +1,5 @@
 on boot
-    mkdir /data/misc/metrics 0700 system system
+    mkdir /data/misc/metrics 0770 system system
 
 service metrics_daemon /system/bin/metrics_daemon --uploader -nodaemon
     class late_start